Class: RelaxDB::Document

Inherits:
Object
  • Object
show all
Includes:
Validators
Defined in:
lib/relaxdb/document.rb

Direct Known Subclasses

MigrationVersion

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Validators

#validator_required

Constructor Details

#initialize(hash = {}) ⇒ Document

Returns a new instance of Document.



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# File 'lib/relaxdb/document.rb', line 117

def initialize(hash={})
  unless hash["_id"]
    self._id = UuidGenerator.uuid 
  end
  
  @errors = Errors.new
  @save_list = []
  @validation_skip_list = []

  # Set default properties if this object isn't being loaded from CouchDB
  unless hash["_rev"]
    properties.each do |prop|
     if methods.include?("set_default_#{prop}")
       send("set_default_#{prop}")
     end
    end
  end
        
  @set_derived_props = hash["_rev"] ? false : true
  set_attributes(hash)
  @set_derived_props = true
end

Instance Attribute Details

#errors ⇒ Object

Used to store validation messages



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# File 'lib/relaxdb/document.rb', line 8

def errors
  @errors
end

#save_list ⇒ Object

A call issued to save_all will save this object and the contents of the save_list. This allows secondary object to be saved at the same time as this object.



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# File 'lib/relaxdb/document.rb', line 13

def save_list
  @save_list
end

#validation_skip_list ⇒ Object

Attribute symbols added to this list won’t be validated on save



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# File 'lib/relaxdb/document.rb', line 16

def validation_skip_list
  @validation_skip_list
end

Class Method Details

.add_derived_prop(prop, deriver) ⇒ Object

See derived_properties_spec.rb for usage



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# File 'lib/relaxdb/document.rb', line 90

def self.add_derived_prop(prop, deriver)
    source, writer = deriver[0], deriver[1]
    derived_prop_writers[source] ||= {}
    derived_prop_writers[source][prop] = writer
end

.after_save(callback) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 510

def self.after_save(callback)
  after_save_callbacks << callback
end

.after_save_callbacks ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 514

def self.after_save_callbacks
  @after_save_callbacks ||= []
end

.all(params = {}) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 461

def self.all params = {}
  AllDelegator.new self.name, params
end

.all_relationships ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 457

def self.all_relationships
  belongs_to_rels + has_one_rels + has_many_rels + references_many_rels
end

.before_save(callback) ⇒ Object

Callbacks - define these in a module and mix’em’in ?



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# File 'lib/relaxdb/document.rb', line 492

def self.before_save(callback)
  before_save_callbacks << callback
end

.before_save_callbacks ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 496

def self.before_save_callbacks
  @before_save ||= []
end

.belongs_to(relationship, opts = {}) ⇒ Object Also known as: references 



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# File 'lib/relaxdb/document.rb', line 422

def self.belongs_to(relationship, opts={})
  belongs_to_rels[relationship] = opts

  define_method(relationship) do
    create_or_get_proxy(BelongsToProxy, relationship).target
  end
  
  define_method("#{relationship}=") do |new_target|
    create_or_get_proxy(BelongsToProxy, relationship).target = new_target
    write_derived_props(relationship) if @set_derived_props
  end
  
  # Allows all writers to be invoked from the hash passed to initialize 
  define_method("#{relationship}_id=") do |id|
    instance_variable_set("@#{relationship}_id".to_sym, id)
    write_derived_props(relationship) if @set_derived_props
    id
  end

  define_method("#{relationship}_id") do
    instance_variable_get("@#{relationship}_id")
  end
  
  create_validator(relationship, opts[:validator]) if opts[:validator]
  
  # Untested below
  create_validation_msg(relationship, opts[:validation_msg]) if opts[:validation_msg]
end

.create_all_by_class_view ⇒ Object

Create a view allowing all instances of a particular class to be retreived



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# File 'lib/relaxdb/document.rb', line 562

def self.create_all_by_class_view
  if RelaxDB.create_views?        
    view = ViewCreator.all
    view.save unless view.exists?
  end        
end

.create_validation_msg(att, validation_msg) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 79

def self.create_validation_msg(att, validation_msg)
  if validation_msg.is_a?(Proc)        
    validation_msg.arity == 1 ?
      define_method("#{att}_validation_msg") { |att_val| validation_msg.call(att_val) } :
      define_method("#{att}_validation_msg") { |att_val| validation_msg.call(att_val, self) } 
  else  
    define_method("#{att}_validation_msg") { validation_msg } 
  end
end

.create_validator(att, v) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 66

def self.create_validator(att, v)
  method_name = "validate_#{att}"
  if v.is_a? Proc
    v.arity == 1 ?
      define_method(method_name) { |att_val| v.call(att_val) } :
      define_method(method_name) { |att_val| v.call(att_val, self) }
  elsif instance_methods.include? "validator_#{v}"
    define_method(method_name) { |att_val| send("validator_#{v}", att_val, self) }
  else
    define_method(method_name) { |att_val| send(v, att_val) }
  end          
end

.create_views(chain) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 583

def self.create_views chain
  # Capture the inheritance hierarchy of this class
  @hierarchy ||= [self]
  @hierarchy += chain
  @hierarchy.uniq!

  if RelaxDB.create_views?
    ViewCreator.all(@hierarchy).save
    __view_by_list__.each do |atts|
      ViewCreator.by_att_list(@hierarchy, *atts).save
    end
  end
end

.has_many(relationship, opts = {}) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 371

def self.has_many(relationship, opts={})
  @has_many_rels ||= []
  @has_many_rels << relationship
  
  if RelaxDB.create_views?
    target_class = opts[:class] || relationship.to_s.singularize.camel_case
    relationship_as_viewed_by_target = (opts[:known_as] || self.name.snake_case).to_s
    ViewCreator.has_n(self.name, relationship, target_class, relationship_as_viewed_by_target).save
  end      
  
  define_method(relationship) do
    create_or_get_proxy(HasManyProxy, relationship, opts)
  end
  
  define_method("#{relationship}=") do |children|
    create_or_get_proxy(HasManyProxy, relationship, opts).children = children
    write_derived_props(relationship) if @set_derived_props
    children
  end      
end

.has_many_rels ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 392

def self.has_many_rels
  # Don't force clients to check its instantiated
  @has_many_rels ||= []
end

.has_one(relationship) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 397

def self.has_one(relationship)
  @has_one_rels ||= []
  @has_one_rels << relationship
  
  if RelaxDB.create_views?
    target_class = relationship.to_s.camel_case      
    relationship_as_viewed_by_target = self.name.snake_case      
    ViewCreator.has_n(self.name, relationship, target_class, relationship_as_viewed_by_target).save
  end
  
  define_method(relationship) do      
    create_or_get_proxy(HasOneProxy, relationship).target
  end
  
  define_method("#{relationship}=") do |new_target|
    create_or_get_proxy(HasOneProxy, relationship).target = new_target
    write_derived_props(relationship) if @set_derived_props
    new_target
  end
end

.has_one_rels ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 418

def self.has_one_rels
  @has_one_rels ||= []      
end

.inherited(subclass) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 569

def self.inherited subclass
  chain = subclass.up_chain
  while k = chain.pop
    k.create_views chain
  end      
end

.property(prop, opts = {}) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 30

def self.property(prop, opts={})
  properties << prop

  define_method(prop) do
    instance_variable_get("@#{prop}".to_sym)        
  end

  define_method("#{prop}=") do |val|
    instance_variable_set("@#{prop}".to_sym, val)
  end
  
  if opts[:default]
    define_method("set_default_#{prop}") do
      default = opts[:default]
      default = default.is_a?(Proc) ? default.call : default
      instance_variable_set("@#{prop}".to_sym, default)
    end
  end
  
  if opts[:validator]
    create_validator(prop, opts[:validator]) 
  end
  
  if opts[:validation_msg]
    create_validation_msg(prop, opts[:validation_msg])
  end
  
  if opts[:derived]
    add_derived_prop(prop, opts[:derived])
  end
end

.references_many(relationship, opts = {}) ⇒ Object

If you’re using this method, read the specs and make sure you understand how it can be used and how it shouldn’t be used



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# File 'lib/relaxdb/document.rb', line 335

def self.references_many(relationship, opts={})
  # Treat the representation as a standard property 
  properties << relationship
  
  # Keep track of the relationship so peers can be disassociated on destroy
  @references_many_rels ||= []
  @references_many_rels << relationship
 
  id_arr_sym = "@#{relationship}".to_sym
  
  if RelaxDB.create_views?
    target_class = opts[:class]
    relationship_as_viewed_by_target = opts[:known_as].to_s
    ViewCreator.references_many(self.name, relationship, target_class, relationship_as_viewed_by_target).save
  end            
 
  define_method(relationship) do
    instance_variable_set(id_arr_sym, []) unless instance_variable_defined? id_arr_sym
    create_or_get_proxy(ReferencesManyProxy, relationship, opts)
  end
  
  define_method("#{relationship}_ids") do
    instance_variable_set(id_arr_sym, []) unless instance_variable_defined? id_arr_sym
    instance_variable_get(id_arr_sym)
  end

  define_method("#{relationship}=") do |val|
    # Don't invoke this method unless you know what you're doing
    instance_variable_set(id_arr_sym, val)
  end           
end

.references_many_rels ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 367

def self.references_many_rels
  @references_many_rels ||= []
end

.up_chain ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 576

def self.up_chain
  k = self
  kls = [k]
  kls << k while ((k = k.superclass) != RelaxDB::Document)
  kls
end

.view_by(*atts) ⇒ Object

Creates the corresponding view and stores it in CouchDB Adds by_ and paginate_by_ methods to the class



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# File 'lib/relaxdb/document.rb', line 528

def self.view_by *atts
  opts = atts.last.is_a?(Hash) ? atts.pop : {}
  __view_by_list__ << atts
  
  if RelaxDB.create_views?
    ViewCreator.by_att_list([self.name], *atts).save
  end
  
  by_name = "by_#{atts.join "_and_"}"
  meta_class.instance_eval do
    define_method by_name do |*params|
      view_name = "#{self.name}_#{by_name}"
      if params.empty?
        res = RelaxDB.rf_view view_name, opts
      elsif params[0].is_a? Hash
        res = RelaxDB.rf_view view_name, opts.merge(params[0])
      else
        res = RelaxDB.rf_view(view_name, :key => params[0]).first
      end            
    end
  end
  
  paginate_by_name = "paginate_by_#{atts.join "_and_"}"
  meta_class.instance_eval do
    define_method paginate_by_name do |params|
      view_name = "#{self.name}_#{by_name}"
      params[:attributes] = atts
      params = opts.merge params
      RelaxDB.paginate_view view_name, params
    end    
  end
end

Instance Method Details

#==(other) ⇒ Object

Returns true if CouchDB considers other to be the same as self



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# File 'lib/relaxdb/document.rb', line 329

def ==(other)
  other && _id == other._id
end

#after_save ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 518

def after_save
  self.class.after_save_callbacks.each do |callback|
    callback.is_a?(Proc) ? callback.call(self) : send(callback)
  end
end

#before_save ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 500

def before_save
  self.class.before_save_callbacks.each do |callback|
    resp = callback.is_a?(Proc) ? callback.call(self) : send(callback)
    if resp == false
      errors[:before_save] = :failed
      return false
    end
  end
end

#conflicted ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 207

def conflicted
  @update_conflict = true
  on_update_conflict
end

#create_or_get_proxy(klass, relationship, opts = nil) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 318

def create_or_get_proxy(klass, relationship, opts=nil)
  proxy_sym = "@proxy_#{relationship}".to_sym
  proxy = instance_variable_get(proxy_sym)
  unless proxy
    proxy = opts ? klass.new(self, relationship, opts) : klass.new(self, relationship)
    instance_variable_set(proxy_sym, proxy)
  end
  proxy     
end

#destroy! ⇒ Object

destroy! nullifies all relationships with peers and children before deleting itself in CouchDB The nullification and deletion are not performed in a transaction

TODO: Current implemention may be inappropriate - causing CouchDB to try to JSON encode undefined. Ensure nil is serialized? See has_many_spec#should nullify its child relationships



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# File 'lib/relaxdb/document.rb', line 471

def destroy!
  self.class.references_many_rels.each do |rel|
    send(rel).clear
  end
  
  self.class.has_many_rels.each do |rel|
    send(rel).clear
  end
  
  self.class.has_one_rels.each do |rel|
    send("#{rel}=".to_sym, nil)
  end
  
  # Implicitly prevent the object from being resaved by failing to update its revision
  RelaxDB.db.delete("#{_id}?rev=#{_rev}")
  self
end

#inspect ⇒ Object Also known as: to_s 



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# File 'lib/relaxdb/document.rb', line 156

def inspect
  s = "#<#{self.class}:#{self.object_id}"
  properties.each do |prop|
    prop_val = instance_variable_get("@#{prop}".to_sym)
    s << ", #{prop}: #{prop_val.inspect}" if prop_val
  end
  self.class.belongs_to_rels.each do |relationship, opts|
    id = instance_variable_get("@#{relationship}_id".to_sym)
    s << ", #{relationship}_id: #{id}" if id
  end
  s << ", errors: #{errors.inspect}" unless errors.empty?
  s << ", save_list: #{save_list.map { |o| o.inspect }.join ", " }" unless save_list.empty?
  s << ">"
end

#new_document? ⇒ Boolean Also known as: new_record?, unsaved?

Returns:

  • (Boolean) 


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# File 'lib/relaxdb/document.rb', line 297

def new_document?
  @_rev.nil?
end

#on_update_conflict ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 212

def on_update_conflict
  # override with any behaviour you want to happen when
  # CouchDB returns DocumentConflict on an attempt to save
end

#post_save ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 228

def post_save
  after_save
end

#pre_save ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 221

def pre_save
  set_timestamps
  return false unless validates?
  return false unless before_save            
  true 
end

#save ⇒ Object

Not yet sure of final implemention for hooks - may lean more towards DM than AR



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# File 'lib/relaxdb/document.rb', line 188

def save
  if pre_save && save_to_couch
    after_save
    self
  else
    false
  end
end

#save! ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 241

def save!
  if save
    self
  elsif update_conflict?
    raise UpdateConflict, self
  else
    raise ValidationFailure, self.errors.to_json
  end
end

#save_all ⇒ Object

save_all and save_all! are untested



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# File 'lib/relaxdb/document.rb', line 233

def save_all
  RelaxDB.bulk_save self, *save_list
end

#save_all! ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 237

def save_all!
  RelaxDB.bulk_save! self, *save_list
end

#save_to_couch ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 197

def save_to_couch
  begin
    resp = RelaxDB.db.put(_id, to_json)
    self._rev = JSON.parse(resp.body)["rev"]
  rescue HTTP_409
    conflicted
    return false
  end      
end

#set_attributes(data) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 140

def set_attributes(data)
  data.each do |key, val|
    # Only set instance variables on creation - object references are resolved on demand

    # If the variable name ends in _at, _on or _date try to convert it to a Time
    if [/_at$/, /_on$/, /_date$/, /_time$/].inject(nil) { |i, r| i ||= (key =~ r) }
        val = Time.parse(val).utc rescue val
    end
    
    # Ignore param keys that don't have a corresponding writer
    # This allows us to comfortably accept a hash containing superflous data 
    # such as a params hash in a controller 
    send("#{key}=".to_sym, val) if methods.include? "#{key}="
  end
end

#set_timestamps ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 308

def set_timestamps
  now = Time.now
  if new_document? && respond_to?(:created_at)
    # Don't override it if it's already been set
    @created_at = now if @created_at.nil?
  end
  
  @updated_at = now if respond_to?(:updated_at)
end

#to_json ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 173

def to_json
  data = {}
  self.class.belongs_to_rels.each do |relationship, opts|
    id = instance_variable_get("@#{relationship}_id".to_sym)
    data["#{relationship}_id"] = id if id
  end
  properties.each do |prop|
    prop_val = instance_variable_get("@#{prop}".to_sym)
    data["#{prop}"] = prop_val if prop_val
  end
  data["relaxdb_class"] = self.class.name
  data.to_json      
end

#to_param ⇒ Object Also known as: id 



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# File 'lib/relaxdb/document.rb', line 303

def to_param
  self._id
end

#update_conflict? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/relaxdb/document.rb', line 217

def update_conflict?
  @update_conflict
end

#validate_att(att_name, att_val) ⇒ Object 



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# File 'lib/relaxdb/document.rb', line 273

def validate_att(att_name, att_val)
  begin
    success = send("validate_#{att_name}", att_val)
  rescue => e
    RelaxDB.logger.warn "Validating #{att_name} with #{att_val} raised #{e}"
    succes = false
  end

  unless success
    if methods.include? "#{att_name}_validation_msg"
      begin
        @errors[att_name] = send("#{att_name}_validation_msg", att_val)
      rescue => e
        RelaxDB.logger.warn "Validation_msg for #{att_name} with #{att_val} raised #{e}"
        @errors[att_name] = "validation_msg_exception:invalid:#{att_val}"
      end
    elsif @errors[att_name].nil?
      # Only set a validation message if a validator hasn't already set one
      @errors[att_name] = "invalid:#{att_val}"
    end
  end
  success
end

#validates? ⇒ Boolean Also known as: validate

Returns:

  • (Boolean) 


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# File 'lib/relaxdb/document.rb', line 251

def validates?
  props = properties - validation_skip_list
  prop_vals = props.map { |prop| instance_variable_get("@#{prop}") }
  
  rels = self.class.belongs_to_rels.keys - validation_skip_list
  rel_vals = rels.map { |rel| instance_variable_get("@#{rel}_id") }
  
  att_names = props + rels
  att_vals =  prop_vals + rel_vals
  
  total_success = true      
  att_names.each_index do |i|
    att_name, att_val = att_names[i], att_vals[i]
    if methods.include? "validate_#{att_name}"
      total_success &= validate_att(att_name, att_val)
    end
  end
        
  total_success
end

#write_derived_props(source) ⇒ Object

The rationale for rescuing the send below is that the lambda for a derived property shouldn’t need to concern itself with checking the validity of the underlying property. Nor, IMO, should clients be exposed to the possibility of a writer raising an exception.



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# File 'lib/relaxdb/document.rb', line 102

def write_derived_props(source)
  writers = self.class.derived_prop_writers
  writers = writers && writers[source]
  if writers 
    writers.each do |prop, writer|
      current_val = send(prop)
      begin
        send("#{prop}=", writer.call(current_val, self)) 
      rescue => e
        RelaxDB.logger.error "Deriving #{prop} from #{source} raised #{e}"
      end
    end
  end
end